title: Pediatric antiphospholipid syndrome: clinical and immunologic features of 121 patients in an international registry.
abstract: OBJECTIVE
  The purpose of this study was to obtain data on the association of antiphospholipid antibodies with clinical manifestations in childhood and to enable future studies to determine the impact of treatment and long-term outcome of pediatric antiphospholipid syndrome.
  
  
  METHODS
  A European registry extended internationally of pediatric patients with antiphospholipid syndrome was established as a collaborative project of the European Antiphospholipid Antibodies Forum and Lupus Working Group of the Pediatric Rheumatology European Society. To be eligible for enrollment the patient must meet the preliminary criteria for the classification of pediatric antiphospholipid syndrome and the onset of antiphospholipid syndrome must have occurred before the patient's 18th birthday.
  
  
  RESULTS
  As of December 1, 2007, there were 121 confirmed antiphospholipid syndrome cases registered from 14 countries. Fifty-six patients were male, and 65 were female, with a mean age at the onset of antiphospholipid syndrome of 10.7 years. Sixty (49.5%) patients had underlying autoimmune disease. Venous thrombosis occurred in 72 (60%), arterial thrombosis in 39 (32%), small-vessel thrombosis in 7 (6%), and mixed arterial and venous thrombosis in 3 (2%). Associated nonthrombotic clinical manifestations included hematologic manifestations (38%), skin disorders (18%), and nonthrombotic neurologic manifestations (16%). Laboratory investigations revealed positive anticardiolipin antibodies in 81% of the patients, anti-beta(2)-glycoprotein I antibodies in 67%, and lupus anticoagulant in 72%. Comparisons between different subgroups revealed that patients with primary antiphospholipid syndrome were younger and had a higher frequency of arterial thrombotic events, whereas patients with antiphospholipid syndrome associated with underlying autoimmune disease were older and had a higher frequency of venous thrombotic events associated with hematologic and skin manifestations.
  
  
  CONCLUSIONS
  Clinical and laboratory characterization of patients with pediatric antiphospholipid syndrome implies some important differences between antiphospholipid syndrome in pediatric and adult populations. Comparisons between children with primary antiphospholipid syndrome and antiphospholipid syndrome associated with autoimmune disease have revealed certain differences that suggest 2 distinct subgroups.
authors.affiliation: Department of Allergology, University Children's Hospital, University Medical Center Ljubljana, Ljubljana, Slovenia. tadej.avcin@kclj.si
authors.forename: Tadej
authors.initials: T
authors.lastname: Avcin
authors.forename: Rolando
authors.initials: R
authors.lastname: Cimaz
authors.forename: Earl D
authors.initials: ED
authors.lastname: Silverman
authors.forename: Ricard
authors.initials: R
authors.lastname: Cervera
authors.forename: Marco
authors.initials: M
authors.lastname: Gattorno
authors.forename: Stella
authors.initials: S
authors.lastname: Garay
authors.forename: Yackov
authors.initials: Y
authors.lastname: Berkun
authors.forename: Flavio R
authors.initials: FR
authors.lastname: Sztajnbok
authors.forename: Clovis A
authors.initials: CA
authors.lastname: Silva
authors.forename: Lucia M
authors.initials: LM
authors.lastname: Campos
authors.forename: Claudia
authors.initials: C
authors.lastname: Saad-Magalhaes
authors.forename: Donato
authors.initials: D
authors.lastname: Rigante
authors.forename: Angelo
authors.initials: A
authors.lastname: Ravelli
authors.forename: Alberto
authors.initials: A
authors.lastname: Martini
authors.forename: Blaz
authors.initials: B
authors.lastname: Rozman
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Meroni
mesh_terms: D000293:Adolescent; D000367:Age Factors; D016736:Antiphospholipid Syndrome / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics / Q000276:immunology; D001327:Autoimmune Diseases / Q000453:epidemiology; D002561:Cerebrovascular Disorders / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D006801:Humans; D007223:Infant; D007511:Ischemia / Q000453:epidemiology; D008297:Male; D012042:Registries; D013927:Thrombosis / Q000453:epidemiology; D020246:Venous Thrombosis / Q000453:epidemiology / Q000235:genetics